Colloidal bromine and process of making the same



Patented Mar. 29, 1934 COLLOIDAL BROMINE AND PROCESS OF MAKING THE SAMEErnest Govett, deceased, late of New York, N. Y., by Ernest H. Govettand Agnes H. Govett, executors, New York, N. Y.; said Ernest Govettassignor to Govett, Ltd, New York, N. Y., a corporatien of New YorkFrance March 15, 1929 4-. Claims.

The invention which forms the subject of the present application (adivision of the copending application of ERNEST Govnrr, deceased, SerialNo. 263,211, filed March 20, 1928 now patent Number 1,810,104 issuedJune 16, 1931) relates to bromine, and its chief object is to provide acolloidal form thereof, capable of making a homogeneous solution inwater. This form of bromine, which is non-toxic and may be used freelyfor medicinal purposes without harmful efiects, is obtained in solidform in what is apparently a hydrate. Another object is to provide asimple and reliable process of producing the colloidal form of bromine.

For making a colloidal form of bromine a process such as that describedfor making colloidal iodine in the aforesaid application of ERNESTGovsrr, Serial No. 263,211, may be followed; that is, first passing thebromine through a reaction with an organic acid such as tannic or gallicacid referred to, then forming an insoluble bromine compound of silver,lead, copper or other suitable metal, preferably mercury, whichinsoluble compound is then decomposed into an insoluble compound devoidof bromine with liberation of the halogen in solution, followed (ifdesired) by evaporation, giving a colloidal bromine hydrate in solidform. However, a modified process is preferred, as will be describedhereinafter.

As stated above, colloidal bromine may be prepared in much the same wayas colloidal iodine. For example the insoluble colloidal bromide ofsilver, lead, copper, bismuth, mercury or other metal is preferablydecomposed by treating the heated bromide with nitric acid, causing,apparently, the reaction weeks for further precipitation and thefiltered solution is heated to about C. When quite cold it is filteredagain, leaving substantially pure hydrogen bromide (HBr) in solution,which is evaporated to dryness. In this step the bromide is broken up.

The preferred method, however, is as follows. Potassium bromate isdissolved in a solution of tannic acid, using 2.25 parts by weight ofthe acid to 1 part of the bromate, and preferably using not more thanabout 150 grams of the acid per liter of the solution. This produces acompound which is believed to be colloidal hydrogen bromide (I-lIBr),and a potassium salt which appears to be a tannate (K014111009). Heatingthe solution to about 70 C. to insure decomposition of all the bromate,a little nitric acid is added, say 1 gram to each 15 grams of bromateused. A violent reaction ensues, due to decomposition of a littlenitrogen pentoxide formed, and nearly all the tannate settles out. Thesolution is filtered off and allowed to stand several weeks, for furtherprecipitation of tannate. It is then filtered again, and the filtrate isheated to about 60 C., and when it has become quite cold it is againfiltered, leaving substantially pure hydrogen bromide in solution. Uponevaporating the solution a reddish powder is obtained which is believedto have the composition Br(I-l2O)5. Any small amount of acid remainingcan be removed by re-solution and reevaporation. The hydrate is stableup to about 100 C. At somewhat high temperature it loses water, behavingthen as if its composition were Br(H O) Both hydrates form homogeneousolutions in water and are stable therein.

As used in the claims, the term water miscible includes a true solutionand a colloidal solution.

In accordance with the statutes we have described the invention ofERNEST Govm'r, deceased, in such detail as will enable others, skilledin the art to which it appertains or to which it is most nearly related,to practice the invention, and we have also stated what we believe to bea correct scientific theory, but we desire it to be understood that wedo not consider the invention limited to such theory or to the detailsreferred to.

What is claimed as the invention of said ERNEST GovE'r'r is:

causing potassium bromate andtannicacid to react with production of ahydrogen bromine compound in solution and potassium tannate, removingthe tannate, and evaporating the hydrogen bromine compound solution todryness whereby the said compound is decomposed and bromine hydrate isobtained in solid form.

3. In a process of preparing a bromine hydrate,

dissolving potassium bromate in a solution of tannic acid whereby ahydrogen bromine compound in solution and potassium tannate areproduced, heating the solution to insure decomposition of all of thebromate, adding a small amount of mwe acid to the solution, wherebysubstantially all the tannate is precipitated, removing the precipitatedtannate and subsequently evaporating the hydrogen bromine compoundsolution to dryness whereby the said compound is decomposed and brominehydrate is obtained in solid form.

4. As a new product, a water miscible nontoxic bromine hydrate which isstable up to 100 C.

ERNEST H. GOVETT, AGNES H. GOVETT, Ewecutors of the Estate of ErnestGovett, Deceased.

